Crossbow Cannibal's sister on chilling childhood moment that unmasked his dark side

A harrowing new documentary launched on Prime Video today (July 12), delves in to one of the most horrifying cases in British criminal history.

Self-professed 'Crossbow Cannibal', Stephen Griffiths, received a life sentence for the savage murders of three sex workers in Bradford. Employing a crossbow to execute his victims, he would subsequently dismember their bodies at his flat, where police uncovered evidence of him cooking and consuming parts of their remains.

After being apprehended at 40, Griffiths chillingly admitted to police that cannibalism was "part of the magic" post-arrest, boasting that he had slain "loads" beyond his confirmed body count.

Despite his claims, he was only ever convicted of the murders of Shelley Armitage, 31; Susan Rushworth, 43; and Suzanne Blamires, 36.

His apprehension followed the unearthing of CCTV footage capturing his assault on Ms Blamires within his housing complex, leading to a whole life order in 2010-a sentence he continues to serve, reports Mirror US.

His harrowing case is now being revisited in a freshly released 90-minute Prime Video documentary, titled The Crossbow Cannibal. An outline for the documentary states: "Griffiths, a self-confessed cannibal, was desperately keen for infamy - a student of criminology that wanted to become an offender, a narcissist who longed for his moment of fame.

"His gruesome murders allowed him to join the ranks of some of Britain's most notorious murderers.

"15 years since the 'Crossbow Cannibal' was arrested, this documentary looks at one of the most gruesome cases in British criminal history, profiling the making of a murderer who drew inspiration from other serial killers."

Within the documentary, Griffiths' own sister Caroline is interviewed and she unveils a significant clue from their childhood that indicated his violent tendencies.

Referring to him as Shaun, his chosen name, she remembered: "Shaun started showing then, when he was young, the first signs of troubling behaviour.

"He'd have been under 10 when he first started stealing. At one point we didn't have a lot so children, you want things, and Shaun wasn't satisfied to just want them. He had to have them."

Following their parents' divorce, his behaviour deteriorated, and he would begin to steal things from neighbours and even his mother.

"He didn't see a problem with stealing from a woman that was already struggling to provide. So from a young age he was problematic and it just escalated over the years, worse and worse," his sister recounted.

"As he got older, the age gap became more apparent between him and my younger brother, six years. I used to worry about what he was capable of because he was quite mean and cruel and could be violent towards myself and my younger brother."

His sister disclosed a cruel system Griffiths devised to justify violence against his siblings, stating: "He developed a points system. If we did something to Shaun, say we went in his stuff and damaged something, he would give you so many points and once you accrued so many points that was his cue that he could punish you.

"There was one night I must have accrued enough points so he launched an attack on me. He would kneel on your arms so you were pinned. I got my hands free and got a glass ash tray and hit him over the head with it.

"He could be a mean, mean boy."

The Crossbow Cannibal is now streaming on Prime Video